Biological Psychology
the scientific study of the links between biological (genetics, neural, hormonal) and psychological processes
Neuroplasticity
the brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience
Neuron
a nerve cell; the basic building block of the nervous system
Cell Body
the part of a neuron that contains the nucleus; the cell’s life support center
Dendrites
a neuron’s often bushy, branching extension that receive and integrate messages, conducting impulses toward the cell body
Axon
the segmented neuron extension that passes messages through its branches to other neurons or to muscles or glands
Myelin Sheath
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next
Glial Cells
cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory
Action Potential
a neural impulse; a brief electrical charge that travels down an axon
Threshold
the level of stimulation required to trigger a neural impulse
Refractory Period
a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state
All-Or-None Response
a neuron’s reaction of either firing (with a full-strength response) or not firing
Synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; the tiny gap at this junction is called the synaptic gap
Neurotransmitters
chemical messengers that cross the synaptic gap between neurons; when released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
Reuptake
a neurotransmitter’s reabsorption by the sending neuron
Endorphins
“morphine within” --natural, opiate-like neurotransmitters linked to pain control and to pleasure
Agonist
a molecule that increases a neurotransmitter’s action
Antagonist
a molecule that inhibits or blocks a neurotransmitter’s action
Nervous System
the body’s speedy, electro-chemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
Central Nervous System (CNS)
the brain and spinal cord
Peripheral Nervous System (PNS)
the sensory and motor neurons that connect the central nervous system to the rest of the body
Nerves
bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs
Sensory (Afferent) Neurons
neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and the spinal cord
Motor (Efferent) Neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Interneurons
neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs
Somatic Nervous System
the division of the peripheral nervous system that controls the body’s skeletal muscles; also called the skeletal nervous system
Autonomic Nervous System (ANS)
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart)
Sympathetic Nervous System
the division of the autonomic nervous system that arouses the body, mobilizing its energy
Parasympathetic Nervous System
the division of the autonomic nervous system that calms the body, conserving its energy
Reflex
a simple, automatic response to a sensory stimulus
Endocrine System
the body’s “slow” chemical communication system; glands and fat tissue that secrete hormones into the bloodstream
Hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
Adrenal Glands
a pair of endocrine glands that sits just above the kidneys and secretes hormones that help arouse the body in times of stress
Pituitary Gland
the endocrine system’s most influential gland; under the influence of the hypothalamus, it regulates growth and controls other endocrine glands
Lesion
tissue destruction
EEG (Electroencephalogram)
an amplified recording of the waves of electrical activity sweeping across the brain’s surface; these waves are measured by electrodes placed on the scalp
MEG (Magnetoencephalography)
a brain-imaging technique that measures magnetic fields from the brain’s natural electrical activity
PET (Positron Emission Tomography)
a technique for detecting brain activity that displays where a radioactive form of glucose goes while the brain performs a task
MRI (Magnetic Resonance Imaging)
a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue; shows brain anatomy
fMRI (Functional MRI)
a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans; show brain function as well as structure
Brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; it is responsible for automatic survival functions
Medulla
the base of the brainstem; controls heartbeat and breathing
Thalamus
the brain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
Reticular Formation
a nerve network that travels through the brainstem into the thalamus; filters information and plays an important role in controlling arousal
Cerebellum
the “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory
Limbic System
neural system located below the cerebral hemispheres; associated with emotions and drives
Amygdala
two lima-bean-sized neural clusters in the limbic system; linked to emotion
Hypothalamus
a neural structure in the limbic system lying below the thalamus; it directs several maintenance activities, helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward
Hippocampus
a neural center located in the limbic system; helps process explicit (conscious) memories–of facts and events–for storage
Cerebral Cortex
the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center
Frontal Lobes
the portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgements
Parietal Lobes
the portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position
Occipital Lobes
the portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields
Temporal Lobes
the portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear
Motor Cortex
a cerebral cortex area at the rear of the frontal lobes that controls voluntary movements
Somatosensory Cortex
a cerebral cortex area at the front of the parietal lobes that registers and processes body touch and movement sensations
Association Areas
areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking
Neurogenesis
the formation of new neurons
Corpus Callosum
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
Split Brain
a condition resulting from surgery that separates the brain’s two hemispheres by cutting the fibers connecting them